public class Test1 {
    public static void main(String[] args) {
        Bj t = new Bj();
        go(t);
        biji s = new biji();
        go(s);
        if (t instanceof Bj){
            Bj a = (Bj)t;
            a.eat();
        }
    }
    public static void go(B p){
        System.out.println("-------");
        p.run();
        System.out.println("-------");
    }
}
